1. Field of the Invention
This invention relates to a shape inputting system in an automatic programming function particularly suitable for graphic recognition processing.
2. Description of the Prior Art
Generally, in a case where it is necessary to convert shop drawings of a workpiece such as working data of a numerical control (NC) machine tool into digital data or to deal with graphics including portions to be changed or amended, it is convenient to utilize an automatic plotting system, i.e. a system in which graphic forming programs are stored in a computer and an operator describes graphics in an interactive process with the computer while viewing the drawing.
In a conventional automatic plotting system, the shape inputting method is performed by the steps of dividing a shape pattern into shape elements and inputting names applied to the respective shape elements together with numerical values corresponding to the respective names to define the shapes in order. However, in the conventional method of the type described above, a shape of a rough graphic of the object to be worked is first recognized as the order for the operator to recognize the graphic of the workpiece, main sizes of the basic graphics, such as longitudinal lines, end surface lines tapered angles are then read out, and the presence, the shape and size of auxiliary graphics, such as C-face and R-face chamferings of details of the graphics are finally recognized. The rough graphic is referred to as "a basic".
As will be understood from the above, the shape inputting method for the conventional automatic plotting system is quite different from the natural graphic recognition order for the operator, so that the conventional shape inputting operation is not smoothly carried out, thus requiring much time and labor.